using System;

using Org.BouncyCastle.Asn1;

namespace Org.BouncyCastle.Asn1.Ocsp
{
	public class OcspRequest
		: Asn1Encodable
	{
		private readonly TbsRequest	tbsRequest;
		private readonly Signature	optionalSignature;

		public static OcspRequest GetInstance(
			Asn1TaggedObject	obj,
			bool				explicitly)
		{
			return GetInstance(Asn1Sequence.GetInstance(obj, explicitly));
		}

		public static OcspRequest GetInstance(
			object obj)
		{
			if (obj == null || obj is OcspRequest)
			{
				return (OcspRequest)obj;
			}

			if (obj is Asn1Sequence)
			{
				return new OcspRequest((Asn1Sequence)obj);
			}

			throw new ArgumentException("unknown object in factory: " + obj.GetType().Name, "obj");
		}

		public OcspRequest(
			TbsRequest	tbsRequest,
			Signature	optionalSignature)
		{
			if (tbsRequest == null)
				throw new ArgumentNullException("tbsRequest");

			this.tbsRequest = tbsRequest;
			this.optionalSignature = optionalSignature;
		}

		private OcspRequest(
			Asn1Sequence seq)
		{
			tbsRequest = TbsRequest.GetInstance(seq[0]);

			if (seq.Count == 2)
			{
				optionalSignature = Signature.GetInstance(
					(Asn1TaggedObject)seq[1], true);
			}
		}

		public TbsRequest TbsRequest
		{
			get { return tbsRequest; }
		}

		public Signature OptionalSignature
		{
			get { return optionalSignature; }
		}

		/**
		 * Produce an object suitable for an Asn1OutputStream.
		 * <pre>
		 * OcspRequest     ::=     Sequence {
		 *     tbsRequest                  TBSRequest,
		 *     optionalSignature   [0]     EXPLICIT Signature OPTIONAL }
		 * </pre>
		 */
		public override Asn1Object ToAsn1Object()
		{
			Asn1EncodableVector v = new Asn1EncodableVector(tbsRequest);

			if (optionalSignature != null)
			{
				v.Add(new DerTaggedObject(true, 0, optionalSignature));
			}

			return new DerSequence(v);
		}
	}
}
